Strictly Slots magagazine, among other periodicals and books, is so full of detailed information about slot and video poker machines that I keep expecting people to have very complex questions for me -- about random number generators or theoretical win percentages or some obscure video poker strategy. However, the question I'm asked most frequently is a simple one: How do I know when it is the right time to quit playing a particular machine?

Although it's a basic query, the answer is not so straightforward. For years I've been compiling a list of answers to the question of "when to walk." I find that they fall into three main categories: mathematical, common sensical, and emotional.

Although the following guidelines are more for the recreational player than the heavy gambler or video poker professional, many of these considerations are the same for both groups of players

• When you're playing a negative-expectation game (one in which the casino has the edge and over the long run you're mathematically guaranteed to lose). Serious gamblers and professionals, whose main interest is profit, will tell you to walk away from that kind of game even before you drop in a single coin. However, the goal of casual players is entertainment; they're looking for the fun factor. They want to play a variety of machines and they don't want to learn complicated strategies. They're hoping for the big win and are depending on luck. However, math can still be their ally. They can "walk" often, bouncing from machine to machine with wild abandon. The more time they spend changing machines instead of actually playing them, the less they will lose. The money they don't lose is money won!

• When a promotion -- one that made a bad or so-so play a good one -- ends. We've played many negative-expectation games when a promotion transformed the casino edge into an advantage for the player. One example of this would be when a slot club offers triple points during Monday Night Football. However, when the triple-point session is over, we're out of there faster than you can say, "From all of us here at ABC, goodnight."

• When you're hungry, tired, or need a bathroom break. When you haven't eaten for a long time, your blood sugar drops and you can't think clearly. When your eyes start to blur from staring too long at a video screen or spinning reels and when your shoulders, arms, and back start to burn from sitting too long in the same position, you will not make wise decisions. Interestingly, a hotel doctor in Vegas whose practice caters mostly to tourists tells me that one of the most common conditions he treats is urinary problems caused by people refusing to leave their machines often enough to answer the call of nature.

• When the environment is not pleasant, comfortable, or healthy. I often have to change machines when the air-conditioning is blasting Arctic air directly down on my already-aching neck and shoulders. Another typical "move" situation comes when the smoke from the cigarette of the person right beside me is drifting straight into my poor allergy-suffering sinuses. You may want to move if the seat is uncomfortable or your chatter-box neighbor is a whining pessimist or a constant complainer.

• When the machine you're playing has a fuzzy or jumpy screen that gives you a headache, or the bill acceptor doesn't work and you hate to feed coins, or there is a sticky video poker button that causes you to make mistakes on your card holding.

• When you've lost the money you budgeted for that particular gambling session. In this instance, walking means straight out of the casino, into your car, and out of the parking lot. There should be no side trips to the cage to cash a check or to the ATM machine to lay your hands on money that you earmarked for other purposes.

• When your partner wants you to quit and join him or her in a non-gambling activity. I don't have exact statistics on how many relationships break up in a casino, but I suspect there are many. Try to consider these "interruptions" as desirable breaks from the intensity of gambling. Besides, even gamblers need to stop and smell the roses.

This consideration is much harder to pin down -- temperamental factors do not worship at the altar of mathematics and are usually unconcerned about good sense. This is a very personal category. The following aren't universal "reasons," because they're often unreasonable to other people. But it is often a good idea to walk

• When you reach your personal win/loss limit. There is no absolute mathematics rule here. But say you previously decided to change machines when you won $100. You win the $100 and you not only don’t quit, but you subsequently lose that $100. You’ve launched yourself into that "if-I'd-only" territory that is so internally disquieting. Quit when you win that $100 even if you just move to the next machine that looks exactly the same. You may lose the $100 at almost the same rate, but that internal broken record playing "if" in your head won't drive you quite so crazy.

• When you're losing AND it's getting to you. A video slot player on "tilt" is tempted to chase his losses by increasing the number of credits he plays per hand, becoming even more frustrated as he loses even faster. A video poker player may sacrifice the advantage of the "long-term" and deviate from the computer-prescribed strategy to hope for short-term success. Even pros and frequent players, who understand volatility and have learned how to take the ups and downs of gambling, will change machines if they get psyched out by a long losing streak that starts to affect accuracy and speed. A "fresh start" on a new machine gives video poker players a chance to take a break, stretch their bodies and rest their minds; feeling better emotionally, they'll again be able to play faster with less likelihood of making errors. Slot players as well can benefit from a refreshing break before jumping back into the fray.

• When you've been up and down for a long period of playing time and finally get even or up a little. Being on a gambling roller coaster is an exhilarating but exhausting ride, and sometimes Brad and I choose to quit a session when we have finally achieved a small win. Sometimes leaving even, or even with a small loss, makes us feel like a big winner, especially if we've climbed out of a deep hole dug at the beginning of our play that day. I often say, "My nerves just cannot take another elevator ride to the basement today."

• When you win a jackpot. However, this is not for the reason that most people give when they do so: "Now this machine won't be due for another jackpot for a long time." Remember, there is no little computer chip that tells the machine not to give a another jackpot right away. The machine has the same mathematical chance to give a jackpot on the next hand as a week later. However, there IS a valid psychological reason for many people to walk after a big win: It's fun to CELEBRATE! Playing a slot or video poker machine always involves a considerable period of time filled with losing streaks -- for the pro or the recreational gambler alike. The joy of winning is a universal human emotion. What we are all looking for is the jackpot! There is no bigger thrill for the machine player than a royal flush or the top-of-the chart payoff. Stop and savor the feeling. Go somewhere to eat with your partner and talk about every little detail that let up to this jackpot. Go shopping and splurge with a little of the jackpot money.. Even if it's not a large life-changing win, stop and take a little walk and smile at everyone to share your happiness.

• When you're getting bored or you just aren't having fun. The tiny group of pros who make their living at the casino machines may have to put in their eight or ten or twelve hours a day, seven days a week, whether they're enjoying or hating every minute of it. But for the rest of us, gambling is entertainment. And when we aren't having fun at our machine, we need to walk.